Saturday, December 31, 2011

This post is for all you New Year's Eve party goers who don't remember where you were or what you did. If that's the case, then you experienced an alcohol-induced blackout. Haven't you always wondered about the clinical manifestations and neurobiological mechanisms of alcohol-induced blackouts? Maybe you have, but you can't remember.

A definitive review of the phenomenon by Rose and Grant (2010) explains that there are two different types of blackout: en bloc, a complete loss of memory for the affected time period; and fragmentary, where bits and pieces of memories remain. The en bloc blackout is more likely to occur when a large quantity of alcohol is ingested within a small time period.

Alcohol primarily interferes with the ability to form new long–term memories, leaving intact previously established long–term memories and the ability to keep new information active in memory for brief periods. ... Blackouts are much more common among social drinkers—including college drinkers—than was previously assumed, and have been found to encompass events ranging from conversations to intercourse. Mechanisms underlying alcohol–induced memory impairments include disruption of activity in the hippocampus, a brain region that plays a central role in the formation of new autobiographical memories.

I would say it's about the very fragile nature of memory during the transition from REM sleep to wakefulness. You can forget very quickly because the dream is poorly consolidated. Sometimes the memory of a dream will pop into your head later in the day, when a related cue arises. Other times you'll remember when getting into bed the next night, because the context triggers the memory.

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About Me

Born in West Virginia in 1980, The Neurocritic embarked upon a roadtrip across America at the age of thirteen with his mother. She abandoned him when they reached San Francisco and The Neurocritic descended into a spiral of drug abuse and prostitution. At fifteen, The Neurocritic's psychiatrist encouraged him to start writing as a form of therapy.